Service And Maintenance Procedures; Annual Inspection; Filters; Induced Draft And Circulating Blower Motors - Bosch BGH96M060B3B Installation Instructions Manual

15 Service and Maintenance Procedures

WARNING: ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Improper servicing could result in dangerous operation, serious
injury, death or property damage.
Before servicing, disconnect all electrical power to furnace.
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When servicing controls, label all wires prior to
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disconnecting. Reconnect wires correctly.
Verify proper operation after servicing.
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WARNING: FIRE, EXPLOSION OR CARBON MONOXIDE
POISONING HAZARD
Failure to replace with proper control could result in fire,
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explosion or carbon monoxide poisoning.
Replace ONLY with the same model number or as specified
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by the manufacturer.

15.1 Annual Inspection

The furnace must be inspected by a qualified installer， or service agency at least
once per year. Inspect the furnace at the beginning of the heating season. This
will ensure that all furnace components are in proper working order and that the
heating system functions appropriately. Pay particular attention to the following
items. Repair or service as necessary.
a. All flue gas carrying areas external to the furnace (i.e. chimney, vent
connector, vent pipe) are clear and free of obstructions.
b. Check for any loose wiring, and correct as needed.
c. Inspect heat exchangers and blowers for corrosion, deterioration, or
deposits of debris. Remove any obstructions.
d. The vent connector is in place, slopes upward and is physically sound
without holes or excessive corrosion.
e. The return-air duct connection(s) is physically sound, is sealed to the
furnace cabinet, and terminates outside the space containing the furnace.
f. The physical support of the furnace is sound without sagging, cracks, gaps,
etc. around the base so as to provide a seal between the support and the
base.
g. There are no obvious signs of deterioration of the furnace.
h. The pilot and burner flames are in good adjustment (by comparison with
pictorial sketches or drawings of the main burner flame and, if applicable,
the pilot burner flame, refer to the Installation, Operation, and Maintenance
Manual for more information).
i. Check the condensate drain and trap for leaks and cracks. Fill the trap with
water. Clean the drain and trap. The trap must be filled with water and the
drain and trap should be cleaned.
Bosch 96% AFUE Condensing Gas Furnace - BTC 770503101 J (06.2023)

15.2 Filters

A return air filter is not supplied with this furnace; however， there must be a
means of filtering the return air. The installer must supply filter(s) at the time of
installation.
Filter maintenance
Improper filter maintenance is the most common cause of inadequate heating or
cooling performance. Clean permanent filter or replace disposable filter once a
month or more frequently as required. When replacing a filter, it must be replaced
with a filter of the same type and size.
Become familiar with filter location and procedures for removal， cleaning and
replacing them. If help is needed, contact the installer of the furnace or a qualified
service person.
Filter removal
Depending on the installation, differing filter arrangements can be applied. A media
air filter or electronic air cleaner can be used as an alternate filter.
Follow the filter sizes given in the Recommended Minimum Filter size (Table 3, page
22) to ensure proper unit performance.
For further details, see your distributor.
Upright filter removal
To remove filters from an external filter rack in an upright upflow installation, follow
the directions provided with external filter rack kit.
Clean, wash and dry a permanent filter. When using a permanent filter, both
sides should be sprayed with a dust adhesive as recommended on the adhesive
container. Spray adhesives for use with permanent filters can be found at some
hardware stores. BE SURE AIRFLOW DIRECTION ARROW POINTS TOWARDS THE
BLOWER.
Inspect filter. If your dirty filter is the disposable type, replace dirty filter with the
same type and size filter. If your dirty filter is a permanent filter, clean as follows:
Clean, wash, and dry a permanent filter. When using a permanent filter,
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both sides should be sprayed with a dust adhesive as recommended on
the adhesive container.
If badly torn or uncleanable, these filters must be replaced by equal
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size permanent, high velocity filters. Throwaway filters must not be
used as replacement for permanent filters.

15.3 Induced Draft And Circulating Blower Motors

The bearings in the induced draft blower and circulator blower motors are
permanently lubricated by the manufacturer. No further lubrication is required.
Check motor windings for accumulation of dust which may cause overheating.
Clean as necessary.

15.4 Flame Sensor (Qualified Service Technicians Only)

Under some conditions， the fuel or air supply can create a nearly invisible coating
on the flame sensor. This coating acts as an insulator causing a drop in the flame
sense signal. If the flame sense signal drops too low, the furnace will not sense the
flame and will lock out. The flame sensor should be carefully cleaned by a qualified
service technician using emery cloth or steel wool. Following cleaning, the flame
sense signal should be 1 to 6 microamps at 115 volts.
Installation Instructions
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